html{
    height:100%;
}

body { 
    height:100%;
    background-color: #fcfcfc;
}

.center {
  position: absolute;
  margin: auto;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  width: 500px;
  height: 200px;
  border-radius: 3px;
  text-align: center;
}

h1 {
    margin-top: -25px;
    font-size: 800%;
}

@media screen and (max-width: 800px) {
    .center {
        position: absolute;
        margin: auto;
        top: 0;
        right: 0;
        bottom: 0;
        left: 0;
        width: 400px;
        height: 300px;
        border-radius: 3px;
        text-align: center;
    }

    h1 {
        margin-top: -25px;
        font-size: 800%;
    }

    p {
        font-size: .8em;
    }
}